JPH0621150B2 - Method for producing epoxy resin - Google Patents

Description

The present invention relates to a method for producing a high-purity epoxy resin. The obtained high-purity epoxy resin is particularly useful as a raw material resin for electronic components such as semiconductor elements and sealing.

[Prior Art] Epoxy resins have been used in various fields of application due to their excellent properties, but with the rapid development of the electronics field in recent years, they have also been used as encapsulants for semiconductor devices and the like. It's coming.

However, in this field, as the density of semiconductor integrated circuits has increased, higher quality has also been required for the sealing material. In other words, there has been a strong demand for a high-purity epoxy resin having a low epoxy equivalent, which eliminates all chlorine impurities and other ionic impurities that cause corrosion of metals in integrated circuits and residual solvents that impair the characteristics of the sealing resin. .

Usually, an epoxy resin is obtained by reacting bisphenol A having a phenolic hydroxyl group or novolac resin with epihalohydrin such as epichlorohydrin in the presence of an acid or basic catalyst, and the produced halohydrin ether is further alkali hydroxide such as sodium hydroxide. Using metal,
It is produced by performing dehydrohalogenation.

However, in the reaction between the phenolic hydroxyl group and epichlorohydrin, an undesired side reaction occurs, and some chlorine does not become a chlorohydrin ether that can be dechlorinated relatively easily by alkali hydroxide, and the bond bonded in the epoxy resin It remains as a chlorine impurity. This bound chlorine impurity cannot be removed by a physical treatment method such as washing or adsorption. It is also possible to carry out dechlorination under harsh conditions using alkali hydroxide or the like, but in this case, it also acts on the glycidyl group of the epoxy resin, and as a result of the ring-opening polymerization reaction, gelation or polymer As a result, a resin having a low epoxy equivalent cannot be obtained. Therefore, it is extremely important to study the reaction conditions of the phenolic hydroxyl group and epichlorohydrin in order to produce an epoxy resin containing less total chlorine impurities.

Various manufacturing methods have been studied in order to obtain an epoxy resin having a small amount of total chlorine impurities. For example, JP-A-54-904
00 describes a method of producing a glycidyl ether of a polyhydric phenol by reacting a polyhydric phenol with epihalohydrin using an alcohol as a solvent. In addition,
No. 59-40831 describes a method for producing a glycidyl ether of phenols by adding an alkali metal hydroxide in the presence of an ether compound and a quaternary ammonium salt.
Further, JP-A-60-31517 describes a method for producing an epoxy resin by reacting a polyhydric phenol with epichlorohydrin in the presence of an alkali metal hydroxide and an aprotic polar solvent.

[Problems to be Solved by the Invention] However, in the above-mentioned JP-A-54-90400, the total chlorine impurity content of the epoxy resin produced is 1500 to 3500 ppm, and there is a problem that the reducing effect is insufficient. Further, in the above-mentioned JP-A-59-40831, it is difficult to remove the phase transfer catalyst, and there is a problem that the quality of the epoxy resin is deteriorated as an ionic impurity. Furthermore, the above-mentioned JP-A-60
-31517 has a problem that it is difficult to remove the aprotic solvent due to its high boiling point.

As described above, it is extremely difficult to manufacture a high-purity epoxy resin by the conventional technique, that is, an epoxy resin that has a long-awaited total chlorine content for sealing integrated circuits is low, does not contain ionic impurities, and does not contain residual solvent. Met. But,
The present inventors have completed the present invention as a result of extensive studies to solve the above problems.

[Means for Solving the Problems] That is, the present inventors have made a reaction between monohydric or polyhydric phenol, epichlorohydrin and alkali metal hydroxide in the presence of alcohols and ketones and / or ethers. Thus, a method for producing a high-purity epoxy resin was invented.

As described above, when the reaction is carried out in the presence of alcohol, a large amount of all chlorine impurities remain in the epoxy resin. However, surprisingly, by using low-boiling point ketones and / or low-boiling point ethers together in an appropriate ratio, total chlorine impurities can be reduced, and epoxy equivalent is small, and high-purity epoxy with no residual solvent or residual catalyst. A resin could be produced. This effect cannot be obtained at all by using ketones and ethers alone or by using a combination of the two.

The monohydric or polyhydric phenol used in the present invention is a monohydric or polyhydric phenol consisting of a phenol unit substituted or unsubstituted with a halogen, an alkyl group, an allyl group, an alkenyl group, an aryl group, a thioaryl group, or an aralkyl group. It is a polyphenol, specifically, phenol, orthocresol, metacresol, paracresol, diphenol, diphenolmethane (bisphenol F), diphenolethane, diphenolpropane (bisphenol A), tetrabrominated bisphenol A, Examples thereof include phenol tonolac, tetramethylbisphenol F, brominated phenol novolac, cresol novolac, bisphenol S, tetramethylbisphenol S, and biphenol, but are not limited thereto.

The alkali metal hydroxide used in the present invention is specifically, but not limited to, sodium hydroxide, potassium hydroxide, and the like. The amount of alkali metal hydroxide used is 0.9 to 1.5 per mol of phenolic hydroxyl group.
Molar is preferred. It is particularly preferably 1.0 to 1.2 mol. When the amount of alkali metal hydroxide used is small, chlorohydrin ether remains, and when it is large, the decomposition reaction of epichlorohydrin is promoted, which is industrially disadvantageous.

Examples of alcohols used in the present invention include aliphatic alcohols having a boiling point range of 50 ° C. or higher and 120 ° C. or lower. Specifically, methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol. ， Sec-butyl alcohol ， te
Examples include, but are not limited to, rt-butyl alcohol. When the boiling point is 120 ° C or higher, it is difficult to distill off under reduced pressure from the resin, and it remains in the resin to deteriorate the quality. If it is less than 50 ° C, it is industrially disadvantageous because a large-scale condenser is required for the vacuum distillation equipment. The amount of these alcohols used is 5-10 per 100 parts by weight of epichlorohydrin.
0 parts by weight is preferable, and particularly preferably 10 to 40 parts by weight. If the amount used is 5 parts by weight or less, the effect of the present invention is not remarkable. If the amount is 100 parts by weight or more, the epoxy equivalent increases,
The quality of the epoxy resin deteriorates.

Examples of the ketones used in the present invention have a boiling point range of 50.
There are aliphatic ketones having a temperature of not lower than 120 ° C and not higher than 120 ° C, and specific examples thereof include acetone and methyl ethyl ketone, but are not limited thereto. When the boiling point is 120 ° C or higher, it is difficult to distill off under reduced pressure from the resin, and it remains in the resin to deteriorate the quality. If it is less than 50 ° C, it is industrially disadvantageous because a large-scale condenser is required for the vacuum distillation equipment. The amount of these ketones used is 1 to 10 per 100 parts by weight of epichlorohydrin.
0 parts by weight is preferable, and particularly preferably 4 to 40 parts by weight. If the amount used is less than 1 part by weight, the effect of suppressing the formation of bound chlorine cannot be sufficiently exhibited. If it exceeds 100 parts by weight, the epoxy equivalent increases and the quality of the epoxy resin deteriorates.

The ethers used in the present invention have, for example, a boiling point range of
There are aliphatic linear and cyclic ethers having a temperature of 50 ° C. or higher and 120 ° C. or lower, and specific examples thereof include diisopropyl ether, dioxane, and tetrahydrofuran, but are not limited thereto. When the boiling point is 120 ° C or higher, it is difficult to distill off under reduced pressure from the resin, and it remains in the resin to deteriorate the quality. If it is less than 50 ° C, it is industrially disadvantageous because a large-scale condenser is required for the vacuum distillation equipment. The amount of these ether compounds used is 1 to 100 parts by weight of epichlorohydrin.
100 parts by weight is preferable, and particularly preferably 4 to 40 parts by weight. If the amount used is less than 1 part by weight, the effect of suppressing the formation of bound chlorine is not sufficiently exhibited. If it exceeds 100 parts by weight, the epoxy equivalent increases and the quality of the epoxy resin deteriorates.

The weight ratio of alcohol to ketone and / or ether used in the present invention is preferably 1: 9 to 9: 1, more preferably 3: 7 to 7: 3.

The amount of epichlorohydrin used in the present invention is preferably 2 to 20 mol, and more preferably 3 to 10 mol, per mol of the phenolic hydroxyl group. If the amount of epichlorohydrin used is small, the unreacted phenolic hydroxyl group reacts with the generated epoxy group, the epoxy equivalent increases, and the quality of the epoxy resin deteriorates. On the other hand, if the amount of epichlorohydrin used is too large, industrial disadvantages such as reduced productivity will occur.

The epoxy equivalent referred to in the present invention is defined by the number of grams of resin containing one equivalent of epoxy group. For total chlorine impurities, dissolve 1g of epoxy resin in 25ml of ethylene glycol monobutyl ether to prepare 1N-KOH propylene glycol solution.
It is measured by adding 25 ml, boiling for 20 minutes, and then titrating with silver nitrate.

In the present invention, the glycidylation reaction of phenols can be carried out, for example, as follows. First, a monohydric or polyhydric phenol is mixed with epichlorohydrin and alcohol in the proportions described above. To this is added the ketone and / or ether in the proportions described above and mixed. The alkali metal hydroxide is added and reacted with stirring.
The reaction can be carried out under normal pressure or reduced pressure. The temperature is preferably maintained at 30 ° C to 100 ° C, more preferably 40 ° C to 70 ° C during the reaction. The alkali metal hydroxide may be added as an aqueous solution or in a solid form, but it is preferable to add it over 1 to 7 hours in order to avoid a rapid reaction. After completion of the reaction, unreacted epichlorohydrin, alcohol, ketone and / or ether, and produced water are distilled off, and then dissolved in a hydrophobic solvent such as methyl isobutyl ketone and toluene to remove insoluble alkali metal salts. To do. A hydrolyzable chlorine removing step may be added if necessary. Hereinafter, the present invention will be described in more detail with reference to examples, but these are examples and the present invention is not limited to the examples.

[Example] Example 1 In a separable flask 2 equipped with a thermometer, a dropping funnel, a stirrer, a cooling tube and a baffle plate, 120 parts by weight of orthocresol volac, 650 parts by weight of epichlorohydrin, 150 parts by weight of isopropyl alcohol, Acetone 100
Part by weight was charged, stirred and dissolved. After heating to 60 ° C., 93 parts by weight of a 48% aqueous solution of sodium hydroxide was dropped from the dropping funnel over 3 hours. During reaction, normal pressure and temperature is 60 ℃
Kept at. After completion of the dropwise addition, the mixture was stirred for 30 minutes to complete the reaction, and then epichlorohydrin, isopropyl alcohol, acetone, and water were distilled off under reduced pressure, and the resin containing the obtained product salt was dissolved in methyl isobutyl ketone, and then the product salt was added. Was removed.

The amount of hydrolyzable chlorine in the epoxy resin solution was measured, a 48% sodium hydroxide solution equivalent to the amount of hydrolyzable chlorine was added, and the mixture was stirred at a reaction temperature of 90 ° C. for 2 hours. Thereafter, the salt formed by washing with water was removed, and the solvent was removed by distillation under reduced pressure to obtain an epoxy resin. The epoxy resin thus obtained had a total chlorine content of 790 ppm and an epoxy equivalent of 206.

Example 2 A reaction was conducted in the same manner as in Example 1 except that 116 parts by weight of bisphenol A was used instead of orthocresol novolac. The total chlorine content of the obtained epoxy resin was 750 ppm and the epoxy equivalent was 188.

Example 3 The reaction was performed in the same manner as in Example 1 except that 150 parts by weight of sec-butyl alcohol was used instead of isopropyl alcohol. The total chlorine content of the obtained epoxy resin was 800 ppm and the epoxy equivalent was 205.

Example 4 A reaction was conducted in the same manner as in Example 1 except that 150 parts by weight of n-propyl alcohol was used instead of isopropyl alcohol. The total chlorine content of the obtained epoxy resin is 800ppm,
The epoxy equivalent was 206.

Example 5 A reaction was performed in the same manner as in Example 1 except that 100 parts by weight of diisopropyl ether was used instead of acetone. The total chlorine content of the obtained epoxy resin is 810ppm, and the epoxy equivalent is
It was 206.

Example 6 A reaction was conducted in the same manner as in Example 1 except that 50 parts by weight of acetone was added and 50 parts by weight of diisopropyl ether was further added. The total chlorine content of the obtained epoxy resin is 800p
The pm and epoxy equivalent were 206.

Comparative Example 1 Reaction was carried out in the same manner as in Example 1 except that the amount of isopropyl alcohol used was 250 parts by weight and acetone was not used. The total chlorine content of the obtained epoxy resin was 1000 ppm, and the epoxy equivalent was 206.

Comparative Example 2 The reaction was performed in the same manner as in Example 1 except that the amount of acetone used was 250 parts by weight and isopropyl alcohol was not used. The total chlorine content of the obtained epoxy resin was 790 ppm and the epoxy equivalent was 220.

Comparative Example 3 A reaction was performed in the same manner as in Example 5 except that the amount of diisopropyl ether used was 250 parts by weight and isopropyl alcohol was not used. The total chlorine content of the obtained epoxy resin was 810 ppm and the epoxy equivalent was 221.

Comparative Example 4 The amount of diisopropyl ether charged was 150 parts by weight,
The reaction was performed in the same manner as in Example 1 except that the amount of acetone used was 100 parts by weight and isopropyl alcohol was not used. The total chlorine content of the obtained epoxy resin was 800 ppm and the epoxy equivalent was 230.

[Effect of the Invention] By using a specific solvent in combination for the reaction as described above, a high-purity epoxy resin having a small amount of total chlorine impurities and no residual solvent or residual catalyst can be produced by an industrially advantageous method. It became so.

Claims (3)

[Claims] 1. When a monohydric or polyhydric phenol, epichlorohydrin and an alkali metal hydroxide are reacted in the presence of alcohols, ketones and / or ethers, the boiling point range at atmospheric pressure is 50 ° C. A method for producing an epoxy resin using alcohols, ketones, and ethers having a temperature above 120 ° C. 2. The method for producing an epoxy resin according to claim 1, wherein the alcohol is isopropyl alcohol. 3. The method for producing an epoxy resin according to claim 1, wherein the ketone is acetone.